Field of the Invention
The present invention relates to a liquid discharging substrate, a printhead, and a printing apparatus.
Description of the Related Art
A printing apparatus includes, for example, a printhead in which a plurality of nozzles for discharging ink are provided. The printhead includes a printhead substrate (a liquid discharging substrate) on which a plurality of printing elements (discharging elements) corresponding to the plurality of nozzles are arrayed. A corner region of the printhead substrate is readily damaged due to a handling error at the time of manufacture or the like. When the printhead substrate is in use, corrosion advances from a corner region due to an ink mist sprayed from nozzles, and the corner region is readily damaged.
Japanese Patent Laid-Open No. 2004-58633 discloses a printhead substrate including a plurality of printing elements and two electrodes arranged to surround the plurality of printing elements. The two electrodes function as a detecting portion for detecting ink leakage in the printhead substrate. When the two electrodes contact ink, a current flows between the two electrodes, thereby detecting the occurrence of ink leakage in the printhead substrate. However, if the two electrodes are damaged due to a handling error at the time of manufacture or the like, it may be impossible to detect ink leakage in the printhead substrate.